Given a JSON stream of the following form:
{ "a": 10, "b": 11 } { "a": 20, "b": 21 } { "a": 30, "b": 31 }
我想将每个对象中的值相加，并输出一个对象，即:
{ "a": 60, "b": 63 }
I'm guessing this will probably require flattening the above list of objects into a an array of [name, value] pairs and then summing the values using reduce but the documentation of the syntax for using reduce is woeful.
Unless your jq has inputs, you will have to slurp the objects up using the -s flag. Then you'll have to do a fair amount of manipulation:
map(to_entries)
| add
| group_by(.key)
| map({
key: .[0].key,
value: map(.value) | add
})
| from_entries
With jq 1.5, this could be greatly improved: You can do away with slurping and just read the inputs directly.
$ jq -n '
reduce (inputs | to_entries[]) as {$key,$value} ({}; .[$key] += $value)
' input.json
Since we're simply accumulating all the values in each of the objects, it'll be easier to just run through the key/value pairs of all the inputs, and add them all up.